Laser-induced thermal transfer processes are well-known in applications such as color proofing and lithography. Such laser-induced processes include, for example, dye sublimation, dye transfer, melt transfer, and ablative material transfer. These processes have been described in, for example, Baldock:, U.K. Patent 2,083,726; DeBoer, U.S. Pat. No. 4,942,141; Kellogg, U.S. Pat. No. 5,019,549; Evans, U.S. Pat. No. 4,948,776; Foley et al., U.S. Pat. No. 5,156,938; Ellis et al., U.S. Pat. No. 5,171,650; and Koshizuka et al., U.S. Pat. No. 4,643,917.
Laser-induced processes use a laserable assemblage comprising (a) a donor element that contains a thermally imageable coating in contact with a receiver element. The laserable assemblage is imagewise exposed by a laser, usually an infrared laser, resulting in transfer of exposed areas of the thermally imageable coating, also referred to as material, from the donor element to the receiver element. The (imagewise) exposure takes place only in a small, selected region of the laserable assemblage at one time, so that transfer of material from the donor element to the receiver element can be built up one pixel at a time. Computer control produces transfer with high resolution and at high speed. The laserable assemblage, upon imagewise exposure to a laser as described supra, is henceforth termed an imaged laserable assemblage.
Known donor elements tend to lack high durability; that is, they can be scratched, tend to block and can inadvertently adhere to many surfaces. Defects resulting from the lack of durability can transfer to the final image resulting in an unacceptable appearance.
Consequently, a need exists for an improved donor element that has improved surface properties such as durability, antiblocking, rub and mar resistance, adhesion and water and humidity resistance.
IR absorbers which are used to facilitate image transfer have been found to negatively impact color purity when added to the thermally imageable layer of the donor element. Thus, a need exists for an IR absorber layer in the donor element separate from the thermally imageable layer.